US First Lady Melania Trump's official portrait released

She's graced the covers of many a fashion magazine, now the White House has released Melania Trump's first official portrait as First Lady.

The photo was taken at the White House although she spends most of her time in New York so young son Barron can continue his schooling.

The White House issued a two-paragraph sentence to accompany the portrait.

"I am honoured to serve in the role of First Lady, and look forward to working on behalf of the American people over the coming years," it says.

In her portrait, taken in the White House private residence, the First Lady looks directly at the camera with her lips parted slightly wearing a black jacket and neckerchief, with her 25-carat 10th anniversary ring on show.

(White House / Supplied)

Her official biography on the White House website trumpets some of her modelling achievements.

"She has graced the covers of Vogue, Harper's Bazaar, British GQ, Ocean Drive, Avenue, In Style, and New York Magazine. Her major layouts include the Sports Illustrated Swimsuit Issue, Allure, Vogue,Self, Glamour, Vanity Fair, and Elle."

There's been some consternation about the Slovenian-born model's decision to stay in New York after the NYPD estimated it costs up to US$146,000 a day to protect the First Lady and Barron while they live in Trump Tower on Fifth Avenue.

That figure goes up to an average daily rate of US$308,000 when President Donald Trump is in New York.

In February, Police Commissioner James O'Neill said Trump Tower "now presents a target to those who wish to commit acts of terror against our country, further straining our limited counterterrorism resources".

A senior aide has previously confirmed the First Lady will move to the White House at the end of the schooling year with Barron.

More than 500,000 people have signed an online petition to get the First Lady to stay at the White House - or pay for the security costs herself.

It says the taxpayer is paying an "exorbitant amount of money" for something which brings no benefit to the county and says it should be cut as a way to "relieve the national debt".